Shift register



States? Patent Office:

Continuation of application' Ser. Not. 50,695, Aug.. 19",

1960." This applicationiApnlfl, 1964, Ser. No. 360,167 1 Claim".(Cl.'340174) This invention. relates to a magnetic core memory'device,and-more particularly to anirnproved 'andtsir'nplified shift register;This application is a continuation of my earlier filed application,Serial No. 50,695 filed August 19, 1960, and entitled Shift Register,nowabandoned.

An object of, theinvention is to provide: a magnetic core memory" andsignalztranslatingdevice havingximproved performance and operation over'a widestempera lure. range.

, Anotherobject is-to. simplify the'wiringof' a shift register. i v iA-further object is to providea v.wiring'scheme for:a shift register"which lessens the electrical. drive require-- ments of the register.

These and other objects will in part be understood from and inpart'iponited out in the following .description'."

In U.S-.i Patent No. 2,995,731 to J. P.Sweeney, there is disclosedan'improved shiftregister wherein a number of. multi-apert-ure magneticcores are connected .in:' se= quence for the transfer from one "core.*to the :next. of a One core is connected to the,

binary one or""zero. next by a respective -coupling loop.'which isthreaded quenceby respective current pulses.

v This shift register circuit is much more.-stable.and. re-' liableinits operation than earlier shift registers. but. even so it hascertain limitations. Each coupling windingbe tween two successivecoreshas-no blocking diode hit and thus would permit an advancedrive pulseapplied to. a succeeding core to act adversely on the preceding.

one. To prevent this, the: cores are provided with a holdwindingin'addition to the-drive windings. The hold .windingis inseries withthe'advancewindings and serves to apply, to the proper'coresintheregister, when an'advance pulse is applied. toeitheradvancewinding'a magnetic field counteracting and .cancelingiout 'thefieldinduced onithe preceding cores by the coupling windings: Thisarrangement works quite well but'thenneedi-for the hold windingimposesan important restriction. For'best' operation. of thetregister thereshouldbe unity turns-ratio between'the hold. andzadvance windings. hold.windingmust be threaded. through the minor output apertures of the coresand because ihESQQPGHUI'CSIfiIB small (about the size of a pin) only alimited number of turns of the holdwinding can bethreadedthrough. This,

assuminga given turns-ratio of holdto'advance'windings,

drive currents or to permit the use of higher drive core The materials,this previously has not beenpossible. present invention eliminatestheneedrfor alholdiwinding and permits'a much larger number of turnsforthe-'ad-.

vance windings.

In accordance with the present invention, in'one specific embodimentthereof, individual multi-aperture cores of a shift register areconnected from one core to. the nextby couplingloops uniquely wound onthe. cores so that even though no blocking diode is used in the loop,there However, the

is still no tendency'for"one-ofthe'driving pulses to feed backward fromone core'to the preceding: one. This eliminates the'need for ahold'windingiand permits'a much larger number ofadvancewindi'rigzturnson each core, these turns beingthreaded.through'themajor aperture andthus being applied easily. Because :the need for the hold'winding iseliminated," there'are' no: residual errow in compensatinggthe unwantedfield and this circuit operates reliably overa wider. temperature rangethan previous 'onesincluding-"the shift" register in. aforesaid patent;

A better 'understanding of the invention "together with a fullerappreciatiomofits many advantages will bestbe gained from the fdllowingdescription"'giveniii-connection with: the .accompanyingdrawings wherein:r.

FIGURE 'l is a schematic representation. of'a shift registerembodyingifeatures of the invention;

FIGURE 2. is a. wiring :diagram of the shift register;

' and.

' FIGURES 3 1,'b, c, d and e are diagramsshowing the conditions of themagnetic lines: of'fliix: inrthevarious cores ofthe register after "eachsuccessive drive pulse;

into odd. (0) and even (E) groups;- For simplicity, only two O coresand: one Eicore aress hown"butzitv isto be understood that. in; acomplete shift register. .there can be a considerablemumber of cores,with-xanrequal v number of cores in eachzgroup, The-physicallayout. andgeneral. wiring configuration-of this. shift register xcan-be generallythecsame'as for the one'disclosed in'rtheaforesaid patent. Here, the:fiiSti O'core; designatedby numeral 11,.

and havinga relatively large.major iaperturex 12, and a:

small. minor 'aperture113. is provided-xwithsan input winding' 14 whichis". threaded I once: througha aperture 13. Wound twice:throughzthis-same. aperture in the relative sense shown is acouplingv1oop-16 whose other end is threaded once throughtherminor'aperture 17""of.E"core. 18. Similarly,'aperture 17 of core 18has two turns of the nextv couplingtloopilt) 1 whichconnects this :coreto the next core in the register, 0 core 21; through'its' minor'aperture22, successive cores in the register (not shown) being'connectedbycoupling loops in: the same. way.

Each of theminor apertures 13,171and 22 of the cores 1 shown; receivesthreeaturns of a prime windingq24- which after "passing through all ofthe minor apertures makes a.

single .pass in' reversexdire'ction throughi-allzrof'the major aperturesof'the cores. Thisewinding .24; als'ofshowniin FIGURET'Z,v is adapted tobe energizedduring operation of the'register :bya relatively long,.sma1lamplitude primingLpulse.

with the advance windings, thoughuof course, they can.

have a common ground: connectioir'as: sh'ownxinzFIG- UREIZ. Furthermore,advance windingrzti'threads only theOIcores and advance windingt28jonlythe :E'Tcores.

Assuming that all' of the. cores'iareeinitially' in the clear state;that is, saturatedswith -tiux in theclockwise direction'and that .thefirst core,iOcore 11,. h'asbeen set by means'ofa suitablecurrentpulseappliedito winding 14,- then thelines offiuxin the-variousrcoreswill be as indicated. .by the short arrows in: FIGURE-13a. In. thiscondition, all of thelines of flux in cores-18*and 21 are clockwise, buthalf 'of thenlinesof fiu'x 'in'core'l l are counter-clockwise.Thereafter, whenr-a prime current is applied to. winding24,certain'lines of'fiux'in the cores, indicated by the. double-headedarrows" in FIGURE 3b will be reversed, theothersingle-headed:arrowsremaim I 5 942} PatenteduApr; 13; 19651 ing thesame as they were in FIGURE 31!. Next, applying an advance to E pulse towinding 26 causes the flux to change as indicated by the double-headedarrows in FIGURE 3c. The next prime pulse causes the change shown inFIGURE 3d and finally, an advance E to 0 pulse applied to winding 28causes the change indicated in FIGURE 3e. This completes a full cycle orshifting sequence for the register and the binary ,one previously storedin core 11 has now been advanced to core 21,

It will be noted in FIGURE 1 that coupling loop 16 encircles the outerleg of the core at minor aperture 13 and the inner leg at minor aperture17 of core 18 in the relative senses indicated. A one-to-one turns ratioin the coupling loop can be used, but two-to-one ratio as shown, insuresthat the flux switched about minor aperture 13 will cause the sameamount of flux to be switched about aperture 17, and so on. Thus, therewill be no loss in the amount of flux transferred from core to corealong the register.

This coupling loop configuration prevents an advance pulse applied to acore from feeding flux backward through a coupling loop, whilst stillpermitting forward fiux transfer. To understand this more readily,consider the flux in E core 18 after the advance 0 to E pulse. The linesof flux about minor aperture 17, as indicated in FIGURE 3c, will be inthe set state, that is, the flux in the inner leg will be up orcounter-clockwise, and the flux in the outer leg down or clockwise.Priming causes the flux to reverse about minor aperture 17, as indicatedin FIGURE 31!, and now the flux in the inner leg is down or clockwise.Thus, when the advance E to 0 pulse is applied, the flux in the innerleg of the core at minor aperture 17 is already clockwise and cannot bechanged, only the counter-clockwise flux in the outer leg can beswitched. Since no flux in the inner leg switches during this advance Eto 0 pulse, no current is induced in coupling loop 16 and hence no fluxin the preceding core 11 can be switched. Thus, there is no need of ahold winding in this circuit.

In a circuit, like the one above, which has been built and successfullyoperated, multi-aperture cores about the size of a small shirt buttonand made of type 5209 ferrite material manufactured by General CeramicsCompany, were used. Six turns of the advance winding on a core permittedgood operation of the register with a peak pulse current of less than 3amperes. This register is simpler to build and has better operatingcharacteristics than previous registers.

The above description is intended in illustration and not in limitationof the invention. Various changes may occur to those skilled in the artand these may be made without departing from the spirit or scope of theinvention as set forth.

I claim:

A shift register circuit for transferring binary intelligence in acontrolled manner comprising a plurality of multia-perture magneticcores each having a major aperture and a minor aperture, the said coresbeing divided into odd and even groups and threaded by a drive circuitcapable of applying drive current to said cores to advance intelligencealong said register through turns linking said cores and experiencingsaid drive current, the said circuit including a first advance windingthreading the major apertures of the cores of one group in a sense toapply clockwise magnetomotive force with respect to the major aperturethereof, a second advance winding threading the major apertures of thecores of the other group in a sense to apply a clockwise magnetomotiveforce to the core material with respect to the major aperture thereof, aprime winding threading in series by several turns the minor aperturesof the cores of both groups in a sense to apply magnetomotive force in acounterclockwise sense relative to said core major aperture and then inseries by a lesser number of turns threading the major apertures of thecores of both groups in a sense to apply a clockwise magnetomotive forcerelative to the major apertures thereof, the said prime windingsincluding a return path to ground isolating said prime windings from thedrive currents supplied by said advance windings, a transfer circuitcomprised of coupling loops linking the cores of the groups with eachcoupling loop encircling the outer leg of magnetic material adjacent thecore minor aperture to the inner leg of magnetic material adjacent theminor aperture of a succeeding core, each loop having more turns linkingthe outer leg of magnetic material than linking the inner leg ofmagnetic material of the succeeding core, the drive circuit whenenergized in the advance, prime. sequence to the odd and even coresserving to switch flux in a given core to transmit intelligence to asucceeding core via said coupling loops.

No references cited.

IRVING L. SRAGOW, Primary Examiner.

